i recently changed my spark plugs and put oem ngk in but i noticed a loss of power should i just do denso iriduim plugs???

 

First off you list vortec with upgrades... What upgrades? If you went to a smaller pulley you should have gone a step colder, not for power neccessarily, just to avoid misfires which can cause a power loss. Also did you torque down the spark plugs correctly? I believe its 18 psi, and the Vortech kit should be gapped around .034 I believe, maybe less if you upped the psi.

 

just header and resonator replaced in the exhaust .... nothing major